In today's Economix post, Casey Mulligan argues that the greater than predicted unemployment numbers should not be ascribed to the negative effect of the stimulus, but rather to bigger than anticipated negative shocks.

We cannot blame the Obama administration for failing to predict June's 9.5 percent unemployment rate. That result just shows the size of the shocks hitting the economy: Even the best forecasters can miss the unemployment rate by almost two percentage points, even when forecasting fewer than six months ahead.

That makes sense, and is in line with my previous post. But he then argues that since we’ve seen little stimulus effect so far, we should cancel the stimulus, since it'd be costly on a per-job basis (and in any case, he believes the effect on GDP to be small [1]). These are interesting assertions meriting further analysis.

Stock-Flow Mismatch

We're all free to use whatever multipliers we